1. Filed of Invention
This invention relates generally to security inspection systems and more specifically to increasing the efficiency or effectiveness of a security inspection system.
2. Description of Related Art
Security inspection systems have come into widespread use. Luggage, whether carry-on or checked, is generally inspected before it is allowed onto an airplane to detect explosives, weapons or other contraband items. Security inspection may also be employed in other settings, such as at entrances to government buildings or at sporting events or other venues where crowds of people are expected to gather. In these and other settings were security inspection systems are used, a large number of people, and their luggage, often need to be inspected in a short period of time.
Techniques have been developed to accurately and quickly inspect luggage so as to provide minimal disruption to the people who may be delayed while the inspection is being performed. Such techniques may involve inspection equipment that uses any of a number of technologies to form an image of objects within a piece of luggage. X-ray radiation is frequently used to form an image of objects within a piece of the luggage. This image may then be analyzed to identify objects and characteristics of those objects, such as shape, density or atomic number. The nature of objects in the luggage may be inferred from these characteristics, allowing an assessment of the likelihood that the luggage contains a threat object.
In some instances, the image is presented to a human user to make that assessment. Though, fully automated and machine-assisted inspection systems are also used in which a computer processes the image to make a threat assessment.
Regardless of how the assessment is made, ensuring safety mandates that a piece of luggage under inspection cannot be cleared if no determination can be made to a high degree of certainty that the item is free of explosives of other threat items. Rather, the item must be “alarmed,” even though it is not certain that the item contains a threat object. Alarmed items may be rerouted for a more careful inspection using other techniques or possibly directed to a human operator for a manual search of the item under inspection. Regardless of how alarmed items are processed, that processing is likely to slow the inspection process, delaying passengers and consuming resources. More often than not, as a result of a higher level of inspection, a determination may be made that the alarmed item does not, in fact, contain any threat item and can subsequently be cleared.